// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h>
using namespace std;
#define REP(i, s, e) for (int i = (s); i < (e); i++)
#define RREP(i, s, e) for (int i = (s); i >= (e); i--)
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define SZ(_a) (int) _a.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;
#ifndef DEBUG
#define cerr if (0) cerr
#endif
const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;
const int MAXN = 400005;
int n;
string s;
ll ans;
int fw[MAXN];
void incre(int i, int x) {
for (; i <= 2 * n; i += i & -i) {
fw[i] += x;
}
}
int qsm(int i) {
int res = 0;
for (; i > 0; i -= i & -i) {
res += fw[i];
}
return res;
}
int qsm(int s, int e) {
return qsm(e) - qsm(s - 1);
}
int main() {
#ifndef DEBUG
ios::sync_with_stdio(0), cin.tie(0);
#endif
cin >> n;
cin >> s;
s = "?" + s;
vll vec;
REP (i, 2, 2 * n + 1) {
if (s[i] == s[1]) {
continue;
}
int u = 1, v = i;
vii eg;
cerr << u << ' ' << v << '\n';
while (u <= 2 * n) {
eg.pb({u, v});
cerr << ' ' << u << ' ' << v << '\n';
u++; v++;
while (u <= 2 * n && s[u] != s[1]) {
u++;
}
if (v > 2 * n) {
v -= 2 * n;
}
while (s[v] == s[1]) {
v++;
if (v > 2 * n) {
v -= 2 * n;
}
}
}
assert(SZ(eg) == n);
for (auto &[u, v] : eg) {
if (u > v) {
swap(u, v);
}
}
sort(ALL(eg));
REP (i, 1, 2 * n + 1) {
fw[i] = 0;
}
ll sm = 0;
for (auto [u, v] : eg) {
sm += qsm(u, v);
incre(v, 1);
}
mxto(ans, sm);
cerr << ' ' << sm << '\n';
vec.pb(sm);
}
bool dec = 0;
bool can = 1;
REP (i, 1, SZ(vec)) {
//assert(vec[i] != vec[i - 1]);
if (vec[i] < vec[i - 1]) {
dec = 1;
} else if (dec) {
can = 0;
break;
}
}
bool can2 = 1;
dec = 0;
REP (i, 1, SZ(vec)) {
//assert(vec[i] != vec[i - 1]);
if (vec[i] > vec[i - 1]) {
dec = 1;
} else if (dec) {
can2 = 0;
break;
}
}
assert(can || can2);
cout << ans << '\n';
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
0 ms |
212 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
0 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
0 ms |
212 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
0 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Runtime error |
9 ms |
468 KB |
Execution killed with signal 6 |
15 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
0 ms |
212 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
0 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Runtime error |
9 ms |
468 KB |
Execution killed with signal 6 |
15 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
0 ms |
212 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
0 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Runtime error |
9 ms |
468 KB |
Execution killed with signal 6 |
15 |
Halted |
0 ms |
0 KB |
- |